# Module 2 – Number Sense: Part 2

##### Getting Started

- Review the module introduction and outcomes to help you gain an understanding of the main topics and expectations.
- Work through each lesson in this module and complete the Check Your Knowledge activity. You can take notes on each lesson by clicking on the “take notes” tab on the bottom right of your screen. You can take notes for each lesson and they will appear on your dashboard. Make sure you save your notes before continuing to another lesson or quiz.
- Complete the Module Quiz and Module Evidence Activity on this page once all lessons are finished in full.

**Note: **If you would like to learn more about this module’s topics, click the Module Toolbox or Module Glossary for additional and supplementary resources.

In Number Sense, Part 2, students will continue working with real world applications of ratio, unit rates, and percentage applications. They will learn to convert decimals, fractions, ratios, and percentages from one form to another as needed. This foundation will lead to advanced problem solving such as sales tax, discounts, and simple interest. Students will learn more mental math by solving percentages without the use of calculators or pencils.

**After completing this Module, you should be able to:**

- Demonstrate computations and order decimals
- Solve multi-step arithmetic and real-world problems involving exact percents.
- Solve real-life problems requiring interpretation and comparison of various representations of ratios, and simplify numerical expressions with rational exponents.
- Solve tax, discount, and simple interest problems using the techniques provided.
- Calculate common percents mentally.

#### Lesson 1 – Decimals

- decimal pointthe dot placed between the whole number and fractional part of a decimal
- equivalent decimalstwo decimals that have the same value, but are not written the same

#### Lesson 2 – Ratios and Proportions

- ratecompares two different types of measurements, such as miles to gallons
- unit pricea unit rate for one item
- unit ratea rate with a denominator of one

#### Lesson 3 – Rational Numbers

- percenta ratio whose denominator is 100
- rational numbersnumbers that can be written as a ratio of two integers

#### Lesson 4 – Percent Applications

- discounta percent off the original price
- interestthe money the bank pays you for investing your money
- percenta ratio whose denominator is 100
- principalmoney you put in the bank
- rate of interesthow much interest you gain based on a percent of the principal; expressed as a percent per year
- sales taxa percent of the purchase price

#### Lesson 5 – Application: Mental Percents

- 100%the whole number
- 200%double the number
- 25%"quarter of the number" or "half of a half"
- 5%half of 10%
- 50%half the number
- multiples of 10%10% of a number times the multiplier
- multiplierthe number you are multiplying by

#### Lesson 1 – Decimals

#### Lesson 2 – Ratios and Proportions

Math Antics – Ratios And Rates

#### Lesson 3 – Rational Numbers

Math Games – Converting between Percents, Fractions, and Decimals

#### Lesson 4 – Percent Applications

#### Lesson 5 – Application: Mental Percents

Math Antics – Finding A Percent Of A Number